1. Field of the Invention
The present invention relates generally to electrical circuits, and more particularly but not exclusively to power supplies.
2. Description of the Background Art
Power supply circuits, such as DC-DC converters, can include a power switch and an output inductor. The power switch can be a metal oxide semiconductor field effect transistor (MOSFET), for example. The switching operation of the power switch is controlled, e.g., by pulse-width modulation (PWM), to maintain a regulated output voltage. The power switch can be used in conjunction with a synchronous diode or synchronously with another power switch.
An integrated power stage device includes the power switch and a power switch driver in the same chip, i.e., in the same integrated circuit (IC) package. Example integrated power stage devices include the Smart Power Stage™ (SPS) devices from Fairchild Semiconductor and DrMOS (integrated driver-MOSFET) devices. An integrated power stage device does not have an integrated switch controller, and is thus typically employed in conjunction with a separate switch controller, such as a PWM controller IC. The PWM controller controls the switching operation of the power switch based on the current through the output inductor.